"Even though the passwords were hashed, it could be possible for a sophisticated thief to derive many of the passwords," Steckler wrote.

As the breach only affected the company's online forum, no payment or license data was affected.

All user passwords will be reset, and all users are being advised to change their passwords on any other sites where they used the same login credentials.

"We are now rebuilding the forum and moving it to a different software platform," Steckler wrote. "When it returns, it will be faster and more secure. This forum for many years has been hosted on a third-party software platform and how the attacker breached the forum is not yet known."